This invention relates to electrical connections and methods of attaching an electric conductor to an electrically conductive terminal.
Electric motors and other electro-magnetic devices typically have direct connect terminals in which the terminal is secured to an electric conductor for a magnet. To attach the conductor to the terminal, some of the conductor""s cladding must first be trimmed to expose an end portion of the conductor""s wire. The exposed end of the wire is then inserted into the terminal. The terminal is then crimped in two locations. One of the crimps secures the exposed end of the wire to the terminal so that the wire is electrically coupled to the terminal. The other crimp secures the conductor""s cladding to the terminal.
The conductor is generally required to be a precise length. Often, too much of the cladding is trimmed during the attaching process. If too much cladding is trimmed, then the cladding is not sufficiently long to reach the terminal. In some cases the cladding can be pulled out a sufficient length from the stator slot to enable the cladding to reach the terminal. In other cases, adjustment of the cladding cannot be accomplished at all.
Because of the difficulties caused by too much of the cladding being trimmed, the prior art has focused on prevention. Presently, the trimming operation is performed via a hand-held device which singes or melts the cladding a fixed distance from the end of the wire. Removing a fixed length of the cladding prevents a situation in which too much of the cladding is trimmed. However, hand-held devices having two-edge singe blades are generally awkward to use and must be rotated 360 degrees around the conductor to produce complete separation. Melting of the cladding sometimes produces an uneven cut, making it difficult to locate and to securely crimp the cladding into the insulation crimp of the terminal. The melting process also produces noxious gasses that require ventilation.
Among the several advantages of the present invention is the provision of an improved method of attaching an electric conductor to an electrically conductive terminal; the provision of such a method in which the electric conductor""s cladding need not be trimmed to a particular length; the provision of such a method in which the cladding need not be trimmed in a particular manner and in which the end of the cladding need not be evenly cut; and the provision of an electrical connection which overcomes the disadvantages of prior art connections.
In general, a method of the present invention is for attaching an electric conductor to an electrically conductive terminal. The electric conductor comprises a wire and a cladding surrounding the wire. The cladding is of an electrically insulative material. The wire has an exposed end portion extending from an end of the cladding. The method comprises placing a sleeve over the electric conductor. The sleeve is of an electrically insulative material. The method further includes positioning the exposed end portion of the wire adjacent the terminal, securing the exposed end portion of the wire to a first portion of the terminal in a manner so that the exposed end portion of the wire is mechanically secured to and electrically coupled to the terminal, moving the sleeve along the electric conductor to a position in which a portion of the sleeve is adjacent the terminal, and securing the sleeve to a second portion of the terminal in a manner so that the sleeve is mechanically secured to the terminal.
Another aspect of the present invention is an electrical connection comprising an electric conductor, an electrically conductive terminal and a sleeve. The electric conductor has a wire and a cladding surrounding the wire, the cladding is of an electrically insulative material. The wire has an exposed end portion extending from an end of the cladding. The terminal has a first portion and a second portion. The sleeve surrounds the electric conductor and is of an electrically insulative material. The exposed end portion of the wire is secured to the first portion of the terminal in a manner so that the exposed end portion of the wire is mechanically secured to and electrically coupled to the terminal and so that the second portion of the terminal is generally between the end of the cladding and the first portion of the terminal. The sleeve is secured to the second portion of the terminal in a manner so that the sleeve is mechanically secured to the terminal. The sleeve covers the end of the cladding and a protected portion of the wire. The protected portion of the wire extends from the first portion of the terminal to the end of the cladding.
Other objects and features will be in part apparent and in part pointed out hereinafter.